1. Field of the Invention
This invention relates to the field of suspensions for disk drives. More particularly, this invention relates to the field of dual stage actuated (DSA) suspensions and methods of attaching the microactuators used therein to the suspension.
2. Description of Related Art
Magnetic hard disk drives and other types of spinning media drives such as optical disk drives are well known. FIG. 1 illustrates a typical prior art hard disk drive and suspension for which the present invention is applicable. The prior art disk drive unit 100 includes a spinning magnetic disk 101 containing a pattern of magnetic ones and zeroes on it that constitutes the data stored on the disk drive. The magnetic disk is driven by a drive motor (not seen in the figure). Disk drive unit 100 further includes a disk drive suspension 105 to which a magnetic head slider 109 is mounted proximate a distal end of load beam 107. Suspension 105 is coupled to an actuator arm 103, which in turn is coupled to a voice coil motor 112 that moves the suspension 105 arcuately in order to position head 109 over the correct data track on data disk 101. Magnetic head slider 109 is carried on a gimbal which allows slider 109 to pitch and roll so that the slider follows the data track on the disk, and allows for such variations as vibrations of the disk, inertial events such as bumping, and irregularities in the disk's surface.
Both single stage actuated disk drives, which include only voice coil motor 112, and dual stage actuated (DSA) disk drives, which also include one or more microactuators somewhere on the suspension to effect fine arcuate movements of the head slider, are well known in the art. An example of a DSA type head suspension is given in U.S. Pat. No. 7,375,930 issued to Yang et al. and assigned to the assignee of the present application. Another example of a DSA suspension is given in Patent Publication No. US 2009/00886379 by Hanya et al. which is incorporated by reference herein. FIG. 3 of Hanya et al. is redrawn and relabeled as FIG. 2 hereto. In the Hanya et al. suspension, two PZT microactuators 21 are attached to suspension 20 at an actuator plate 23 that is formed integral with base plate 22. Conductive adhesive 24 provides an electrical connection between PZTs 21 and actuator plate 23. Referring now to FIG. 4 of Hanya et al., a known method of electrically and mechanically attaching the PZT microactuators to the suspension is to mechanically affix the PZTs to the microactuator plate by a non-conductive adhesive 51. A small amount of conductive adhesive 53a is then placed on top such that it touches both the top surfaces of the PZT's metallized top face and the actuator plate, thus bridging the gap therebetween and forming a ground connection to the PZT's negative electrode. The positive (driving voltage) connection to the PZT is made on the metallized bottom face of the PZT, which constitutes the PZT's positive electrode, by connecting a wire to the PZT face by conductive adhesive.